Improved HTML Structure for Better Accessibility and Maintainability

[eagleanurag]

Commit Description:

Semantic Sectioning and Class Names:
    Updated class names to be more descriptive.
    Ensured better readability and maintainability.

Alt Text for Images:
    Added alt attributes to all <img> tags to improve accessibility.

SVG Elements:
    Added appropriate role attributes to SVG elements.

External Links:
    Updated external links to open in a new tab using target="_blank".
    Added rel="noopener noreferrer" for security reasons.

CSS Separation:
    Inlined styles for demonstration purposes but recommended moving them to a separate stylesheet for better separation of concerns.

If this pull request (PR) pertains to Chinese-to-English translation, please confirm that you have read the contribution guidelines and complete the checklist below:

• [x] This PR represents the translation of a single, complete document, or contains only bug fixes.
• [x] The translation accurately conveys the original meaning and intent of the Chinese version. If deviations exist, I have provided explanatory comments to clarify the reasons.

If this pull request (PR) is associated with coding or code transpilation, please attach the relevant console outputs to the PR and complete the following checklist:

• [x] I have thoroughly reviewed the code, focusing on its formatting, comments, indentation, and file headers.
• [x] I have confirmed that the code execution outputs are consistent with those produced by the reference code (Python or Java).
• [x] The code is designed to be compatible on standard operating systems, including Windows, macOS, and Ubuntu.

[CodeDance2023]

good

[krahets]

Thanks for the PR! Could you help update docs/index.html and zh-hant/index.html also?